1. Field of the Invention
The present invention relates to a technology for a method of predicting energy consumption, an apparatus for predicting energy consumption, and a terminal apparatus.
2. Description of the Related Art
Efficient usage of energy for vehicles has become an issue due to the development of environmental problems and the like. Therefore, for example, for a navigation system for prediction of energy consumption, an energy saving technology that searches a route that requires less energy consumption and the like have been devised. In such an energy saving technology, it is necessary to predict the energy consumption of a vehicle. Energy consumption referred to herein includes both electrical energy consumption and fuel consumption.
As a method of predicting the energy consumed by a vehicle for driving, presented are a method using a physical model for calculation of the energy consumption of a vehicle and a method based on actual values of energy consumption in the past.
As a method using a physical model, a method is presented that performs calculation from the equations of motion, using the three dimensional shape of a road, a result of prediction of the driving pattern with respect to the driving velocity and acceleration/deceleration of a vehicle, vehicle parameters representing the characteristics of energy consumption categorized by vehicle, and the like.
As a method based on actual values of energy consumption in the past, a method is presented that collects data on energy consumption, velocity, vehicle type, etc. by probe vehicles, and performs prediction at the time of prediction, based on actual results of collected data in the past. Herein, a probe vehicle refers to a vehicle that transmits data obtained by a sensor mounted on the vehicle and operational history of a driver to a navigation server by communication means such as wireless wave, a LAN (Local Area Network), internet connection by a wireless LAN, a mobile phone, or the like.
An example of prediction of energy consumption based on collected data (actual results) by probe vehicles is a technology disclosed by Japanese Patent Application Laid-open No. 2008-20382. In this technology, first, a navigation server collects, by probe vehicles, data on fuel consumption on respective road sections, identification data for identifying vehicle types and models, and operation data which indicates the velocity and acceleration/deceleration of vehicles and the operation of devices. Then, the navigation server builds a database in which fuel consumptions are sorted by the identification data and the operation data and are statistically processed. At the time of predicting fuel consumption, a result of searching data, from the database, that corresponds to the identification data and operation data on a target vehicle is used as prediction of the fuel consumption.